‘They say it’s Belsize Lane,’ Vee reported back to the knitting circle, though half of them had already hurried away to check on their own windows. Vee stayed to help Mrs Lunn clear the floor and tack some muslin across the empty frames, and then she pushed the unfinished sock into her straw bag and set off back to the Vale of Health.

When you took the turning off East Heath Road, it was like walking back into the countryside – a muddy track leading downward through a belt of woodland; you half expected to smell manure and hear a tractor coughing into life, and then the track curved and the purplish bricks of ‘Taormina’ came into sight between the trees, and suddenly it was all fanlights and balustrades, and name-boards swinging from wrought-iron brackets. The choice of names always puzzled Vee: if you had so much money that you could afford to live here, why didn’t you just up sticks and move to Braemar or Greenbanks or St Ives? Though given that half the houses were currently empty, the windows shuttered, the gardens a wilderness, perhaps the inhabitants had done exactly that.

Vee had just passed ‘Llandudno’ when she heard Noel call ‘Mar!’, and she turned to see him hurrying to catch up, limping slightly, as he sometimes did when he ran.

‘There was a buzz bomb!’ he said, his voice breaking mid-sentence, so that ‘buzz’ was shrill with tension, and ‘bomb’ a growl.

‘I didn’t think you’d be back yet,’ said Vee. It hadn’t occurred to her to worry about him, and she felt a rush of belated anxiety. ‘You weren’t anywhere near it, were you?’

‘No. What about you?’

‘Miles away,’ she said. ‘Barely heard it.’ He was a terrible worrier, his shoulders up around his ears as he inspected her for possible damage. She patted his arm. ‘What have you been doing? Your hands are black.’

‘Oh.’ He gave them a perfunctory wipe, his expression relaxing back to its usual blank watchfulness. ‘I was looking at a mediaeval roof boss.’

‘Were you?’ She turned the phrase over in her head, but she couldn’t face an explanation till she’d had a cup of tea. ‘Did you get the books?’

‘No. The shop’s vanished.’

‘Vanished?’

‘It was hit by a V-2.’ He paused, thinking. ‘The interesting thing is that a whole row of houses was flattened, but the staircases survived, and I’ve been wondering if that has to do with the fact that they’re right-angled triangles.’

‘What?’

‘The triangle is an inherently strong shape. Look at the Pyramids, still intact after thousands of years.’

‘But no one ever bombed them.’

‘But you can’t imagine them collapsing if someone did. Would you prefer to spend a raid in a tower or a Pyramid?’

‘A tower. Less cleaning up afterwards – think of the floor space in a Pyramid; it’d be sweep, sweep, sweep all day.’

He cracked a smile. ‘Incidentally, I quite badly need the Bright’s English History – Mr Jepson says it’s essential for matriculation.’